Wire-connector



March 10., 1910 D. mmgm ETAL 3,500,292 1 WIRE-CONNECTOR Filed July 12, 1968 United States Patent 3,500,292 WIRE-CONNECTOR Dennis J. Enright, St. Paul, and Richard D. Kahabka,

Burnsville Village, Minn., assignors to Minnesota Mining and Manufacturing Company, St. Paul, Minn., a

corporation of Delaware Filed July 12, 1968, Ser. No. 744,422 Int. Cl. H01r 9/08 US. Cl. 339-97 3 Claims ABSTRACT OF THE DISCLOSURE A wire-connector, having a spring-metal contact element including a cylindrical socket and a bifurcate wire receiving plate within a folding plastic insulative body, for application to an insulated wire in providing a plug-andsocket tap connection therewith.

This invention relates to wire-connectors. There is provided a contact element which may be attached directly to an insulated wire to provide a permanent spring loaded solderless tap or T contact therewith for subsequent connection of a wire-end fitted with a snap plug terminal. The device is particularly useful in making plug-andsocket connections with continuous wires, e.g. in the wiring of automobiles and other vehicles.

The contact elements described in US. Patent No. 3,388,370 include a modification which similarly provides means for attaching a plug receptacle to an insulated run wire. In this prior art connector the contact element is inserted and pressed into the insulating body at the time of making the connection, and an attached cover is then folded over the exposed end of the contact member. In the connector of the present invention, the contact element is permanently retained in position within the insulating body; and electrical contact is completed, and the insulating body permanently closed, in a single operatiOn.

In the drawing,

FIGURE 1 is a view in perspective of the connector attached to an insulated run wire and in position to receive a snap plug;

FIGURE 2 is a view, in perspective and with a portion cut away to show detail, showing the connector in open position for application to the Wire;

FIGURE 3 is a plan view of the flat blank from which the contact element is formed;

FIGURE 4 is a plan view showing the insulating body; and

FIGURE 5 is a sectional elevation taken approximately along line 55 of FIGURE 4.

The connector is shown in FIGURE 2 to consist of a spring metal contact element 11 within a plastic insulating body 12. The body is foldable about a central longitudinal fold line 13 into the configuration shown in FIGURE 1. It contains opposing first half-channels 14, 15 adjacent and parallel to the fold line 13, and opposing second half-channels 16, 17 adjacent the first half-channels. The body is slotted across each of the second halfchannels to provide transverse slots 18, 19. Additional openings 20, 21 are provided adjacent the ends of slot 18, and extended post-like members 22, 23, 24 and 25 are positioned adjacent the ends of the slot 19. Semicir-cular opposing ridges 26, 27 and 28, 29 are provided within the inner half-channels 14, 15, which channels are widened in diameter at the open end and are closed at the other end by semicircular walls 30, 31.

A narrow hook member 32 is formed at one side of the body 12 and in position to interlock with a latch mem- 3,500,292 Patented Mar. 10, 1970 her 33 provided at the opposite side when the body is closed by folding about the fold line 13.

The contact element 11 includes a bifurcate contact member 34 comprising resiliently connected first and second contact lobes 35, 36 having generally parallel contact surfaces for making resiliently loaded electrically conductive contact with a wire forced therebetween, and having a doubly toothed base for insertion within slot 19. The bifurcate member is formed integrally with a generally cylindrical receptacle 37 prepared from the flat rectangular portion 38 of the blank of FIGURE 3, the two being connected by an intervening bridge 39. The receptacle 37 fits between the semi-circular ridges 27, 29 in half-channel 15 when the base of the bifurcate member 34 is forced into the slot 19, a narrow channel 40 being provided in the wall separating the halfchannels 15 and 17 for receiving the bridge 39.

The side margins of the contact lobes 35, 36 are supported between posts 22, 23 and 24, 25 respectively; and these posts fit into the openings 20, 21 when the body is closed. Likewise, the ends of the lobes 35, 36 then fit within the channel 18, the lobes lying on both sides of a central darn 41 which, together with the remainder of the inner surface defining the half-channel 16, supports the wire 42 to which contact is to be made.

In a typical example, for a connector designed to be applied to insulated run wires of 14 to 18 gage, the body 12 has an overall extended width from book 32 to latch 33 of 1.25 inches and the overall length, as applied to the wire, is 1.1 inches. The nominal thickness of the body, exclusive of projecting hook, latch and peg components, is 0.18 inch, which is reduced to .012 inch along the fold line 13. The body is desirably made of polypropylene, although other tough plastic insulating materials are also useful; one such material is nylon polyamide polymer. To assure a tight fit between the extended portions defining the open end of the first tubular channel, the free sides 45, 46 of the half-channels 14, 15 are slanted slightly above the plane of the remainder of the side edges of these half-channels, as shown in FIGURE 2.

The rectangular section 38 of the blank of FIGURE 3 is .5 inch in length and .25 inch in width and is spaced .07 inch from the near edge of the lobe 35. The two lobes are .16 inch in length and the channel between the two lobes is .027 inch in width. The toothed base of the element 34 extends .09 inch beyond the end of the channel. The section 38 is formed into the generally cylindrical receptacle 37 which has a circular front opening, at the end farthest from the bridge 39, for easy entry of a snap plug 43, and is provided with a slight indent 44 near said end for releasably retaining said plug. The receptacle is slightly flattened toward the rear opening to provide a tight spring fit for the plug.

In order to make elfective spring contact with snap plug 43 the receptacle 37 must be highly resilient. No. 26 gage cartridge brass having a thickness of 0.0159 inch is a preferred material for this component. On the contrary, the bifurcate contact element 34 is normally required to be of more sturdy construction, spring brass of ,6, inch thickness being employed in the element of US. Patent No. 3,388,370. The present connector makes possible the effective utilization in the contact element of the much less bend-resistant thinner metal plate by incorporation of reinforcing support posts 22-25.

It will be apparent from the preceding description, taken in connection with the drawing, that contact with a wire 42 is made simply by laying the wire in the halfchannel 16, folding the body 12 about the fold line 13, and then forcing it shut against the resiliency of the element 11 as the lobes 35, 36 penetrate the insulating wirecovering and make electrical contact with the conductor.

33 which is resiliently displaced, and attains the locked closed position indicated in FIGURE 1. The result is the permanent application to the wire of the contact receptacle for a snap plug, by means of which electrical contact may be made between the wire 42 and such plug. Sufficient pressure for making the connection may be applied with simple hand tools such as pliers. The conductive element 11 is and remains completely contained within the insulating plastic body 12.

In its open position the wire-connector of this invention will be seen to be an integral device. The contact element 11 is securely anchored within the plastic body 12 by the action of the hook components of the base 34 on the end walls of the channel 19 as well as by the frictional engagement between the margins of the lobes 35, 36 and the supporting posts 22, 23, 24 and 25. The latter provide a further advantage in supporting the connecting lobes in a position perpendicular to the plane of the base and in line with the slot 18 when the body 12 is folded into the closed position, while permitting spring separation of the lobes 35, 36 in making resilient contact with the conductor.

What is claimed is as follows:

1. A solderless wire-connector for providing a snap plug receptacle on an insulated run wire, comprising: a one-piece contact element, consisting of a resilient splittube receptacle portion and a bifurcate flat wire-contacting portion, and a one-piece hard tough foldable insulative body member having opposing first half-channels adjacent the fold line and opposing second half-channels adjacent said first half-channels, said body member when folded providing a first tubular channel for said receptacle portion and a parallel second tubular channel for a wire to which said bifurcate wire-contacting portion is to be connected; said body being interiorly sloted transversely of each said second half-channels to provide op- 0 At the same time, the hook 32 presses beneath the latch mit ting the same to be driven into insulation-penetrating and resiliently loaded wire-contacting engagement with a said wire lying along the open one of said second-halfchannels; said body being provided with opposing posts extending at each side of one of said slots for supporting the side margins of said bifurcate member and with opposing openings correspondingly at each side of the other of said slots for receiving said posts upon closure of said wire-connector; and said body further being provided at its outer edges with opposing resilient interlocking latch means for maintaining the connector in closed position after folding.

2. The Wire-connector of claim 1 wherein said first half-channels are closed at one end to provide a closed end wall at one end of said first channel and removed from said split-tube receptacle by a ditsance sufiicient to accommodate the free end of a snap plug removably retained within said split-tube receptacle.

3. The wire-connector of claim 2 wherein said first half-channels contain arcurate ridges at each end of the position of said split-tube receptacle to retain said receptacle in position while permitting terminal access thereto with a snap plug connector.

References Cited UNITED STATES PATENTS 3,388,370 6/1968 Elm 339-98 3,425,023 1/1969 KIOl et al. 339 59 FOREIGN PATENTS 699,856 11/1953 Great Britain.

RICHARD E. MOORE, Primary Examiner J. H. MCGLYNN, Assistant Examiner 

